Thumb sucking is a very common habit in babies and young children; Stanford Children’s Health states that around nine in 10 newborn babies display some kind of hand sucking within two hours of birth. 

Most children stop this kind of behavior between two and four years old, but some continue on for years. If your child sucks their thumb, you may be wondering if it’s a potential problem. 

From an orthodontist’s point of view, here’s what you should know about thumb sucking. 

What Thumb Sucking Does to the Bite 

Excessive thumb sucking can adversely affect a child’s smile. The pressure exerted by both the thumb itself and the sucking can cause teeth to move and alter the way the jaw develops. Here are three ways thumb sucking can affect your child’s smile:  

• The thumb pushes the lower teeth in and presses the upper teeth out
• The inward suction can lead to the jaws growing more narrowly
• The top front and top bottom teeth don’t meet, leading to an “open bite” 

The severity of these effects depends in part on your child’s teeth and on how much they suck their thumb. 

When Thumb Sucking Becomes a Problem 

Many parents want to know at what age thumb sucking becomes a true problem. There’s no direct answer to this question because it depends on the degree of the habit. Some children suck their thumb for just a few minutes a day while others have their thumb in their mouth for hours at a time. 

In general, as long as the thumb sucking stops before losing the first baby tooth and getting adult teeth (around age 6), any effects can naturally reverse themselves. It’s when your child continues to suck their thumb after adult teeth start coming in that problems can develop. At this point, as a parent you can and should intervene to help your child break the habit. 

Breaking the Habit for Good 

First, it’s important to understand that while orthodontic treatment can address the tooth and jaw issues caused by thumb sucking, the results will only last as long as the habit is gone. One patient in our office sucked her thumb to the point where she had an open bite, which was corrected with braces. When she came back for a check-up much later, the open bite was back – and she admitted she’d gone back to sucking her thumb. Only after kicking the habit for good were we able to achieve a straight, healthy smile – permanently. 

For tips on helping your child break the habit, check out these tips from Colgate. 

Being Proactive to Prevent Problems 

There’s nothing any of us can do about genetics and the teeth we were naturally born with, but we can do something about our habits. The same is true for your children. If you see them developing bad habits, whether that’s thumb sucking, finger sucking, lip biting, tongue thrusting, etc., work with them and with your orthodontist and/or dentist to correct those habits now so they don’t lead to problems later.